• Journal of fish pathology
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• v.13 no.2
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• pp.111-119
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• 2000

One hundred and twenty three strains of bacterial flora collected from Kunsan bay and examined for drug resistance to 9 antibiotics. The isolated and examined bacteria were Vibrio spp.(44 strains), Pseudomonas spp.(42 strains), Aeromonas spp.(26 strains), Moraxella spp.(9 strains), Enterobacteria spp.(6 strains), Bordetella spp.(3 strains), Alkaligenesis spp.(3 strains), Staphylococcus spp.(3 strains), and Flavobacterium spp.(2 strains). The drugs used were Ampicillin(AM), Penicillin-G(PM), Rifampicin(RF), Streptomycin(SM), Oxolinic acid (OA), Nalidixic acid(NA), Oxytetracycline(OT), Amikacin(AK), and Enorfloxacin(EF). Forty two strains were found to be sensitive to all drugs. The remaining strains showed resistance to various combinations of drugs. Among the resistant strains were mostly restricted to AM(54 strains/43.9%), PM(47 strains/38.2%), RF(35 strains/28.4%), SM(9 strains), OA(5 strains/ 4.06%), and NA(1 strains/0.8%), in combination at high degree showing 15 different drug resistant patterns. The most frequently showed resistant patterns were AM-PM-RF(16 strains/13.4%), AM-PM(8 strains/6.5%), and PM-RF(7 strains/5.6%). These results suggested that Kunsan bay were contaminated with various strains of highly resistant strains to drugs(AM, PM and RF). These results suggest that high levels of various antibiotics have already been introduced to Kunsan bay. Furthermore it seems that chemotherapy of fish disease has become extremely difficult because of the acquirement of multi-drug resistance to wide range of antibiotics.

• Tuberculosis and Respiratory Diseases
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• v.49 no.4
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• pp.412-420
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• 2000

Background : There is increasing concern in many countries about the problem of drug-resistant tuberculosis. Prevalence of primary drug-resistant tuberculosis is the optimal epidemiological indicator for long term monitoring of national tuberculosis control program. Our purpose was The purpose of our study is to assess clinical characteristics and socioeconomic status of patients with drug-resistant tuberculosis. Method : We studied 68 cases with drug-resistant Mycobacterium tuberculosis infection diagnosed at the Ewha Womans University Mokdong Hospital from March, 1995 to February, 2000. Results : Patients with primary drug-resistant tuberculosis(PDR) were younger (39.6$\pm$16.3 years vs. 48.2$\pm$16.5 years ; p<0.05), had more population of less than more were under the age of 40 years aged -group(62.9% vs. 36.4% ; p<0.05) and were more highly educated than those with acquired drug-resistant tuberculosis(ADR)(38.9% vs. 11.1% ; p<0.05). In patients with ADR, the rates of familial history of tuberculosis and living in a rented house residence in a rented house were increased higher than compared with to those of patients with PDR. Patients with ADR had more involved lobes(2.0$\pm$0.8 vs. 1.4$\pm$0.7 ; p<0.01) and longer treatment duration than those with PDR(18.3$\pm$7.2 months vs. 10.6$\pm$6.3 months ; p<0.05). Patients with ADR showed larger numbers of resistant were resistant to more number of drugs, lower hospitalization rate and higher rate of self-interruption of medication than those with PDR. In patients with PDR, mono-drug resistance was increased, whereas poly- and multi-drug resistances were decreased compared with those with ADR. Resistance to isoniazid was the highest among antituberculosis drugs, and resistance to isoniazid in patients with ADR was higher than that in patients with PDR(90.9% vs. 71.4% ; p<0.05). Conclusions : Patients with ADR were more likely to include more population be of lower socioeconomic class, and patients with PDR seem seemed to be young and socially active population. For control of drug-resistant Mycobacterium tuberculosis infection, proper isolation and prevention of patient with drug-resistant tuberculosis are needed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.1005-1009
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• 2013

Using DNA sequencing method, we analyzed mutations of rpoB (RNA polymerase beta subunit) rifampin-resistant Mycobaterium tuberculosis strains which were identified by conventional test at Masan National Hospital and The Korean Institute of Tuberculosis. Though it has been reported different mutations of rpoB region of rifampin-resistant M. tuberculosis strains in the south of Korea, it is not confirmed whether these mutations of rpoB region actually express rifampin resistance through experiment. We confirmed experimentally these mutations of rpoB region of M. tuberculosis strains induced rifampin-resistance through ampified rpoB by polymerase chain reaction (PCR) and cloning of mutant rpoB into rifampin sensitive-M. tuberculosis strain.

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.250-256
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• 2005

Background : Fluoroquinolone drugs are an important anti-tuberculous agent for the treatment of multi-drug resistant tuberculosis. However, many drugs belonging to the fluoroquinolones have different cross resistance to each other. Methods : Sixty-three ofloxacin (OFX) resistant and 10 pan-susceptible M. tuberculosis isolates were selected, and compared for their cross resistance using a proportion method on Lowenstein-Jensen media, containing ofloxacin (OFX), ciprofloxacin (CIP), levofloxacin (LVX), moxifloxacin (MXF), gatifloxacin (GAT) and sparfloxacin (SPX), at concentrations ranging from 0.5 to $3{\mu}g/ml$. DNA extracted from the isolates was directly sequenced after amplifying from the gyrA and gyrB genes. Results : The 63 OFX resistant M. tuberculosis isolates showed complete cross resistance to CIP, but only 90.5, 44.4, 36.5 and 46.0% to LVX, MXF, GAT, and to SPX, respectively. Fifty-one of the isolates (81.0%) had point mutations in codons 88, 90, 91 and 94 in gyrA, which are known to be correlated with OFX resistance. The Gly88Ala, Ala90Valand Asp94Ala mutations in gyrA showed a tendency to be susceptible to MXF, GAT and SPX. Only 4 isolates had mutations in the gyrB gene, which did not affect the OFX resistance. Conclusion : About 60% of the OFX resistant M. tuberculosis isolates were susceptible to GAT, SPX and MXF. These fluoroquinolones may be useful in the treatment of TB patients showing OFX resistance.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.61-67
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• 2009

Purpose : The rate of drug-resistant tuberculosis (DR-TB) in children is an indicator of the effectiveness of TB control programs in the community. This study aimed to assess the prevalence of DR-TB in children and evaluate TB management. Methods : Between January 1999 and July 2007, drug susceptibility tests for anti-TB drugs were employed for patients aged less than 19 years with culture-positive TB. Results : A total of 607 cases (16.6%) were resistant to at least one anti-TB drug as follows: isoniazid (INH; 13.8%), rifampin (8.9%), pyrazinamide (4.2%), streptomycin (3.7%), ethambutol (EMB; 5.9%), and para-aminosalicylic acid (PAS; 1.9%). Multidrug-resistant (MDR) TB was found in 276 cases (7.6%); extensive drug resistant (XDR) TB, in 5 cases (0.2%). The rate of resistance to at least one anti-TB drug in children aged >15 years (16.1%) was significantly lower than that in children aged <15 years (20.5%) (P=0.016). The rate of resistance to at least one anti-TB drug and multidrug-resistance in this survey decreased significantly (P<0.001) as compared to the previous survey (1987-1995). The rate of resistance to INH, EMB, and PAS also significantly decreased (P<0.05). Conclusion : The rate of DR-TB in children in Korea has decreased over time; however, it remains higher than that in other countries. MDR-TB and XDR-TB are the emerging problems in Korean children. Therefore, the selection of effective drugs through drug susceptibility tests and evaluating risk factors of resistant TB is essential to successful therapy and a decreased incidence of DR-TB.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.37-37
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• 2019

벼 재배포장에서 화학약제의 반복적인 사용으로 인한 병원균의 약제내성과 환경오염은 커다란 문제가 되고 있다. 이러한 약제내성을 극복하기 위한 노력의 하나로 유전자수준의 약제내성기작의 규명과 대체물질의 발굴이 필요하다고 사료된다. 이에 본 연구에서는 식물종이 지니는 광범위한 다양성에 주목하였고, 700여 종의 식물추출물을 벼 도열병균에 처리해 균사성장억제효과를 조사하는 선별실험을 실시하였고, 영릉향과 지모추출물이 높은 균사성장억제효과를 보이는 것을 확인했다. 영릉향과 지모 추출물이 화학약제를 대체하는 대안물질로서 가능성을 조사하기위해 균사성장억제능력 확인실험, 분획, HPLC (High Performance Liquid Chromatography), 포자발아 및 부착기 형성확인검정, ABC transporter의 발현조사, 환경독성실험등을 실시했다. 실험 결과, 영릉향과 지모 추출물을 벼 도열병균에 처리하였을 때 약제저항성유전자 ABC transporter의 기능이 저하되고 화학약제에 대한 내성이 감소를 확인했으며, 분획과 HPLC분석을 통해 영릉향과 지모의 유효성분을 확인했다. 또한, 실제 포장에서 영릉향 추출물과 지모 추출물을 사용하여 벼 도열병 방제가를 확인하는 포장시험을 실시한 결과, 각각 63%와 62%의 목 도열병 방제가를 확인 하였으며, 인축환경에 대한 유해성을 조사하기 위해 어류, 설치류, 중치류, 곤충을 대상으로 영릉향 추출물을 처리해 급성독성시험 실시한 결과, 고농도의 투여량에서도 독성이 없는 것을 확인했다. 위의 실험 결과를 토대로, 영릉향과 지모추출물이 화학농약에 의한 환경오염을 막을 수 있고, 인축과 환경에 피해를 입히지 않는 친환경자재로 친환경적인 생물농약의 신소재로서 가능성을 나타냈다고 사료된다.

• Korean Journal of Weed Science
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• v.17 no.2
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• pp.176-184
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• 1997

The rice(Oryza saliva L.) tolerance to herbicide thiobencarb was determined. At the concentration of thiobencarb 3.0kg ai/ha, Yamabiko, M73 (23)F.A, and wx 139-3-64-220-3-1 were the most tolerant among 643 rice genotypes tested. Thiobencarb reduced plant height until 14 days after treatment by 10% and 13% in tolerant and susceptible genotypes, respectively, but increased plant height in 21 days after treatment for both the genotypes, though partial stunting or dwarfing was observed during the early period until 14 days after treatment. Number of tillers per plant was greater in the plants treated by thiobencarb than in the control, showing that the tolerant genotypes had 2 to 3 tillers which were more than the susceptible ones. Regardless of the genotypes, shoot dry weight was increased by 30 to 50% in 35 days after thiobencarb treatment. The root dry weight increased by 50 to 100% in 35 days after the treatment.

• 보건세계
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• v.50 no.12 s.568
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• pp.46-47
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• 2003

• 보건세계
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• v.43 no.1 s.473
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• pp.4-7
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• 1996

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.31-39
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• 2007

This study has been carried out for investigating the relatedness of representative 135 Shigella sonnei strains isolated from 2000 to 2004 by using biotyping and antimicrobial resistance. All strains showed typical biochemical characterisics of Shigella strain. Among 135 strains,79 (58.5%) strains were biotype "g",54 (40.0%) strains were biotype "a" and 2 (1.5%) strains were biotype "e". The results of susceptibility test against 16 antimicrobial agents were like this. Most of strains were susceptible to AN, CIP, C and GM. 129 (95.6%) strains were resistant to SXT, 126 (93.3%) strains were resistant to TE and 122 (90.4%) strains were resistant to SM. One hundred thirty two (97.8%) strains were resistant to more than two antimicrobial agents. R28 type (antimicrobial resistance patterns 28: resistant to AM, SAM, TE, TIC, SXT, K, SM and AmC) were 42 strains (31.1%). The other strains were showed 33 kinds of R patterns. The results of $bla_{TEM}$, sulII, tetA and strA gene detection were coincided with phenotype of antimicrobial resistance by disk diffusion method. But some strains which had sulII and strA genes were not showed the resistance against SXT and SM.